JP2005049844A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which can supply exact currents to EL pixels without receiving the influence of variation even if the signal currents are small in transistors for supplying the currents to EL pixels. <P>SOLUTION: Video signal voltages are dot sequentially and successively inputted to respective signal lines. This voltage corresponds to the precharging operation to the video signal currents to be thereafter inputted. The video signal currents are inputted to the respective signal lines after inputting of the video signal voltages. The influence of the variations in the transistors of the respective pixels can be thereby reduced. Also, the video signal voltages are inputted before the input of the video signal currents and therefore even if the magnitdude of the signal currents is small, a signal writing speed is made faster. Since the video signal voltages are dot sequentially inputted, the exact supply of the currents is realized by the simple configuration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor device having a function of controlling a current supplied to a load with a transistor, and particularly includes a pixel formed of a current-driven light-emitting element whose luminance changes depending on the current, and a circuit for supplying a signal to the pixel. The present invention relates to a semiconductor device.

In a display device using a self-luminous light-emitting element typified by an organic light-emitting diode (OLED (Organic Light Emitting Diode)), an organic EL element, or an electroluminescence (EL) element, a driving method thereof is used. The simple matrix method and the active matrix method are known. Although the former has a simple structure, there is a problem that it is difficult to realize a large-sized and high-brightness display. In recent years, an active matrix system in which a current flowing through a light emitting element is controlled by a thin film transistor (TFT) provided in a pixel circuit is used. Development is underway.

In the case of an active matrix display device, a problem has been recognized that the current flowing through the light emitting element changes due to variations in the current characteristics of the driving TFT, resulting in variations in luminance. In other words, a driving TFT that drives a current flowing through the light emitting element is used in the pixel circuit, and the current flowing through the light emitting element changes due to variations in characteristics of these driving TFTs, resulting in variations in luminance. It was. Thus, even if the characteristics of the driving TFT in the pixel circuit vary, the current flowing through the light emitting element does not change, and various circuits have been proposed for suppressing variations in luminance (see, for example, Patent Documents 1 to 4).
Patent Application Publication No. 2002-517806 International Publication No. 01/06484 Pamphlet Patent Application Publication No. 2002-514320 International Publication No. 02/39420 Pamphlet

  Patent Documents 1 to 3 disclose circuit configurations for preventing fluctuations in the current value flowing through the light emitting element due to variations in characteristics of the driving TFTs arranged in the pixel circuit. This configuration is called a current writing type pixel or a current input type pixel. Patent Document 4 discloses a circuit configuration for suppressing changes in signal current due to variations in TFTs in a source driver circuit.

  FIG. 6 shows a first configuration example of a conventional active matrix display device disclosed in Patent Document 1. 6 includes a source signal line 601, first to third gate signal lines 602 to 604, a current supply line 605, TFTs 606 to 609, a holding capacitor 610, an EL element 611, and a current source 612 for inputting video signal current. Have.

  The operation from signal current writing to light emission will be described with reference to FIG. In the figure, the figure numbers indicating the respective parts are the same as those in FIG. 7A to 7C schematically show the current flow. FIG. 7D shows the relationship between the currents flowing through the respective paths when signal current is written. FIG. 7E shows the voltage accumulated in the storage capacitor 610 when signal current is written, that is, TFT 608. This shows the gate-source voltage.

  First, a pulse is input to the first gate signal line 602 and the second gate signal line 603, and the TFTs 606 and 607 are turned on. At this time, the current flowing through the source signal line, that is, the signal current is defined as Idata.

Since the current Idata flows through the source signal line, as shown in FIG. 7A, the current path is divided into I ₁ and I ₂ in the pixel. These relationships are shown in FIG. Needless to say, Idata = I ₁ + I ₂ .

At the moment when the TFT 606 is turned on, no charge is held in the storage capacitor 610, so the TFT 608 is turned off. Therefore, I ₂ = 0 and Idata = I ₁ . That is, during this time, only a current due to charge accumulation in the storage capacitor 610 flows.

Thereafter, electric charges are gradually accumulated in the storage capacitor 610, and a potential difference starts to occur between the two electrodes (FIG. 7E). When the potential difference between the two electrodes becomes Vth (point A in FIG. 7E), the TFT 608 is turned on and I ₂ is generated. As described above, since Idata = I ₁ + I ₂ , I ₁ gradually decreases, but current still flows, and charge is stored in the storage capacitor.

In the storage capacitor 610, charge accumulation continues until the potential difference between the electrodes, that is, the gate-source voltage of the TFT 608 reaches a desired voltage, that is, a voltage (VGS) that allows the TFT 608 to pass the current Idata. . When the accumulation of charges is finished (point B in FIG. 7E), the current I ₁ stops flowing, and further, the TFT 608 flows a current corresponding to the VGS at that time, and Idata = I ₂ (FIG. 7B )). Thus, a steady state is reached. Thus, the signal writing operation is completed. Finally, selection of the first gate signal line 602 and the second gate signal line 603 is completed, and the TFTs 606 and 607 are turned off.

  Subsequently, the light emission operation is started. A pulse is input to the third gate signal line 604, and the TFT 609 is turned on. Since the VGS written earlier is held in the storage capacitor 610, the TFT 608 is turned on, and the current Idata flows from the current supply line 605. As a result, the EL element 611 emits light. At this time, if the TFT 608 operates in the saturation region, Idata can flow without change even if the source-drain voltage of the TFT 608 changes.

  Such an operation for outputting the set current is referred to as an output operation. As a merit of the current writing type pixel, even when the characteristics of the TFT 608 are varied, the storage capacitor 610 holds the gate-source voltage necessary for the current Idata to flow. There is a point that current can be accurately supplied to the EL element, and therefore, variation in luminance due to variation in TFT characteristics can be suppressed.

The above example relates to a technique for correcting a change in current due to variations in driving TFTs in a pixel circuit, but the same problem occurs in a source driver circuit. Patent Document 4 discloses a circuit configuration for preventing a change in signal current due to manufacturing variations of TFTs in a source driver circuit.
Patent Application Publication No. 2003-66908

  Further, in Patent Document 5, a voltage source is prepared in addition to a current source for controlling gradation, and a voltage source is supplied at the beginning of a row selection period by power source switching means for switching between two power sources input to the source signal line. Discloses a configuration in which the electric charge of the stray capacitance is instantaneously changed, and then gradation display is performed by the current source 10 in order to obtain a desired luminance.

  However, since the parasitic capacitance of the wiring used for supplying the signal current to the driving TFT and the light emitting element is extremely large, when the signal current is small, the time constant for charging the parasitic capacitance of the wiring is increased, and the signal writing speed is increased. There is a problem that it becomes slow. That is, even if a signal current is supplied to the transistor, it takes a long time to generate a voltage necessary to flow the transistor at the gate terminal, and the signal writing speed becomes slow. Yes.

  Therefore, Patent Document 5 discloses a configuration in which the charge of the source signal line is changed instantaneously, but the voltage value supplied at the beginning of the row selection period is not optimal. In addition, the configuration has become complicated.

  In view of such problems, the present invention reduces the influence of transistor characteristic variation, can supply a predetermined current, and can sufficiently improve the signal writing speed even when the signal current is small. An object is to provide an apparatus.

  The present invention achieves the above object by supplying an optimal voltage in advance when inputting to a pixel.

    The present invention is a semiconductor device including a circuit for controlling a current supplied to a load by a transistor, wherein the source or drain of the transistor is connected to a current source circuit, and current is supplied from the current source circuit to the transistor. And an amplifying circuit for controlling the gate-source voltage and the drain-source voltage of the transistor.

    The present invention is a semiconductor device comprising a video voltage signal line, a plurality of signal lines, a plurality of voltage control switches, a plurality of current source circuits, and a plurality of current control switches, wherein the signal lines are The video voltage signal line is connected via the voltage control switch, and the current source circuit is connected to the signal line via the current control switch.

    According to the present invention, a video current signal line for supplying a current to the current source circuit is provided according to the configuration.

    According to the present invention, there is provided a drive circuit that sequentially selects the voltage control switch according to the configuration.

    The present invention is characterized in that a drive circuit for sequentially supplying current from the video current signal line to the current source circuit is provided.

    According to the present invention, a voltage / current supply circuit that supplies a signal current to the video current signal line and supplies a signal voltage to the video voltage signal line is provided.

    According to the present invention, the signal voltage is a precharge voltage to a pixel connected to the signal line.

  In the present invention, the type of applicable transistor is not limited, and a thin film transistor (TFT), a semiconductor substrate, or an SOI (Silicon On Insulator) substrate using a non-single crystal semiconductor film typified by amorphous silicon or polycrystalline silicon. MOS transistors, junction transistors, transistors using organic semiconductors or carbon nanotubes, and other transistors can be used. There is no limitation on the kind of the substrate over which the transistor is provided, and the transistor can be provided over a single crystal substrate, an SOI substrate, a glass substrate, or the like.

  In the present invention, being connected is synonymous with being electrically connected. Therefore, in the configuration disclosed by the present invention, in addition to a predetermined connection relationship, another element (for example, another element or a switch) that enables electrical connection may be disposed therebetween.

  In the present invention, the influence of transistor characteristic variation can be reduced, a predetermined current can be supplied, and the signal writing speed can be sufficiently improved even when the signal current is small. In addition, by adjusting the size and current amount of each transistor, it is possible to supply a precharge voltage having an optimum magnitude.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode.

In the present invention, a pixel is formed using an element whose light emission luminance can be controlled by a value of a current flowing through the light emitting element. Typically, an EL element can be used. Although there are various known EL element configurations, any element structure can be applied to the present invention as long as the emission luminance can be controlled by the current value. That is, an EL element is formed by freely combining a light emitting layer, a charge transport layer, or a charge injection layer. As a material therefor, a low molecular weight organic material, a medium molecular weight organic material (without sublimation, In addition, an organic light-emitting material having a monomer unit of 20 or less or a chained molecule having a length of 10 μm or less) or a polymer organic material can be used. Moreover, you may use what mixed or disperse | distributed the inorganic material to these.

  FIG. 1 shows an example of the overall configuration. A plurality of pixels 109aa to 109ad are connected to the signal line 102a. Similarly, a plurality of pixels 109ba to 109bd are connected to the signal line 102b, and a plurality of pixels 109ca to 109cd are connected to the signal line 102c.

  The signal line 102a is connected to the video voltage signal line 101 via the voltage control switch 104a, and is connected to the current source circuit 107a via the current control switch 105a. Similarly, the signal line 102b is connected to the video voltage signal line 101 via the voltage control switch 104b, and is connected to the current source circuit 107b via the current control switch 105b. The same applies to the signal line 102c. The voltage control switches 104a to 104c are controlled by the voltage control shift register 103 via sampling selection lines 106a, 106b, and 106c.

  Next, the operation of FIG. 1 will be described. First, as shown in FIG. 2, the voltage control switch 104a is turned on by the voltage control shift register 103, and the video signal voltage is input from the video voltage signal line 101 to the pixel 109aa. The magnitude of the video signal voltage at this time is assumed to be a magnitude corresponding to the display of the pixel 109aa.

However, at this time, the video signal voltage is not necessarily input to the pixel 109aa. It is sufficient that the potential of the signal line 104a is charged to the video signal voltage.

  Next, as shown in FIG. 3, the voltage control switch 104b is turned on by the voltage control shift register 103, and the video signal voltage is input from the video voltage signal line 101 to the pixel 109ba. The magnitude of the video signal voltage at this time is assumed to be a magnitude corresponding to the display of the pixel 109ba.

  Similarly, as shown in FIG. 4, the voltage control switch 104c is turned on by the voltage control shift register 103, and the video signal voltage is input from the video voltage signal line 101 to the pixel 109ca.

  Next, as shown in FIG. 5, the current control switches 105a to 105c are turned on, and video signal currents are input from the current source circuits 107a to 107c to the pixels 109aa to 109ca. The magnitude of the video signal current at this time is assumed to be a magnitude corresponding to the display of each pixel.

  At this time, as shown in FIGS. 2 to 4, the video signal voltage is input prior to the input of the video signal current. Therefore, at the time when the video signal voltage is input, the potential of the signal lines 102a to 102c is approximately equal to that when the video signal current is input in FIG. 5 to be in a steady state (that is, when the signal input is completed). It has become. However, the current characteristics of the transistors in the pixels 109aa to 109ca may vary. In such a case, when the video signal voltage is input and when the video signal current is input to reach a steady state (that is, when the signal input is completed), the potential of the signal lines 102a to 102c is set. There is a difference. Therefore, as shown in FIG. 5, by inputting the video signal current, the influence of the variation in the current characteristics of the transistors in the pixels 109aa to 109ca is reduced. As a result, variation in luminance of each pixel can be reduced, and display with accurate luminance can be achieved.

  That is, it can be considered that the operations in FIGS. 2 to 4 correspond to the precharge operation before the video signal current is input in FIG. 2 to 4, the video signal voltage is not necessarily input to each pixel because this operation corresponds to a precharge operation. Of course, it goes without saying that a video signal voltage may be input to each pixel in FIGS.

  With such an operation, even if the magnitude of the video signal current is small, the steady state (completion of signal input) can be quickly achieved.

  Further, the magnitude of the video signal current changes in accordance with the luminance. Therefore, it is not easy to control the magnitude of the video signal voltage (pre-charge voltage) in accordance with it. To realize this, it is necessary to use many circuits. Therefore, the layout area increases, the power consumption increases, the manufacturing yield decreases, and the cost increases. However, in this application, since the video signal voltage (precharge voltage) is supplied to each pixel from the video voltage signal line 101 by dot sequential driving, the magnitude of the video signal voltage (precharge voltage) can be easily controlled. is there. Further, since the circuit configuration is simple, problems such as an increase in layout area, an increase in power consumption, a decrease in manufacturing yield, and an increase in cost can be avoided.

By the operation as described above, the input of the video signal to the pixels 109aa to 109ca in the first row is completed. Next, signals are input to the pixels 109ab to 109cb in the second row as in FIGS. Similarly, video signals are input from the third row onward.

  As described above, in FIGS. 2 to 5, one horizontal period is divided into two, the video signal voltage (precharge voltage) is input in the first half, and then the video signal current is input in the second half. However, it is not limited to this.

  For example, after FIG. 2, the operation may be performed as illustrated in FIG. 8, then as illustrated in FIG. 9, and then as illustrated in FIG. 5. That is, as shown in FIGS. 2 to 5, the period for inputting the video signal voltage (precharge voltage) and the period for inputting the video signal current are not divided into the first half and the second half of one horizontal period. As shown in FIG. 8, FIG. 9, and FIG. 5, the video signal current may be sequentially input after the input of the video signal voltage (precharge voltage) is completed. By doing so, it is possible to provide a longer period for inputting the video signal current. When the period for inputting the video signal current is long, the signal current can be sufficiently written, so that the influence of transistor variation can be reduced.

  However, in this case, the period in which the video signal current is input differs between a column (for example, the signal line 102a) in which the video signal current is input in the early order and a column (for example, the signal line 102c) in which the video signal current is input in the late order. End up. As a result, in a column (for example, the signal line 102c) in which the video signal current is input is short, there is a possibility that the steady state may not be sufficiently reached. Therefore, the video signal voltage and the video signal current may not be always input in order from the signal line 102a, but may be input in order from the signal line 102c. Such a change in order may be performed by switching every row or every frame period.

  In the configuration of FIG. 1, only one video voltage signal line 101 is shown, but the present invention is not limited to this. As shown in FIG. 10, a plurality of video voltage signal lines 101a and 101b are arranged, and video signal voltages (precharge voltages) are simultaneously input to a plurality of signal lines (102a, 102b, 102c, etc.). Also good.

  In the configuration of FIG. 1, the video voltage signal line 101 and the signal lines 102a, 102b, and 102c are connected via the voltage control switches 104a, 104b, and 104c, but the present invention is not limited to this. For example, as illustrated in FIG. 11, voltage storage circuits 1101a and 1101b may be disposed between the voltage control switch 104a and the signal line 102a and between the voltage control switch 104b and the signal line 102b. The voltage storage circuits 1101a and 1101b have a function of outputting an input voltage. Further, when a voltage having a certain value is input, the previously input voltage may be output at the same time. By arranging such a circuit, the timing of signal input can be made more flexible.

  In the configuration of FIG. 1, the pixels are arranged in 4 rows and 3 columns, but the present invention is not limited to this, and an arbitrary number of pixels may be arranged.

  In the configuration of FIG. 1, the number of signal lines is three (signal lines 102a to 102c), but is not limited thereto. Any number may be arranged.

  In the configuration of FIG. 1, it is described that current flows from each pixel to the current source circuit 107a and the like, but the present invention is not limited to this. The direction of the current can be changed depending on the circuit configuration of the pixel.

(Embodiment 2)
In the first embodiment, the case where one signal line is arranged for one column of pixels has been described. In this embodiment mode, a case where a plurality of signal lines are arranged for one column of pixels is described.

  Here, for the sake of simplicity, a case is shown in which two signal lines are arranged per pixel for one column and the pixels are arranged in four rows and two columns. However, it is not limited to this. An arbitrary number of signal lines may be arranged for one column of pixels, or an arbitrary number of pixels may be arranged.

  As shown in Embodiment Mode 1, when one signal line is arranged for one column of pixels, it is necessary to input one column of signals to the pixels during one horizontal period. It was. Therefore, for example, a video signal voltage (precharge voltage) is input in the first half of one horizontal period, and a video signal current is input in the second half. In such a case, since the period for inputting the video signal current to the pixel is not sufficiently long, there may be a case where the signal input has to be terminated without being able to reach a steady state (completion of signal input). .

Thus, by arranging a plurality of signal lines for one column of pixels, the period for inputting the video signal current to the pixels can be extended.

Therefore, FIG. 12 shows a configuration diagram in the case where two signal lines are arranged per pixel for one column and the pixels are arranged in four rows and two columns. In the pixel in the first column, signal lines 1202aa and 1202ab are arranged, pixels in even rows are connected to the signal line 1202aa, and pixels in odd rows are connected to the signal line 1202ab. As a result, signals can be simultaneously input to the pixels for two rows. The signal lines 1202aa, 1202ab, 1202ba, and 1202bb are connected to the video voltage signal line 101 through voltage control switches 1204aa, 1204ab, 1204ba, and 1204bb, respectively. The signal lines 1202aa and 1202ab are connected to the current source circuit 107a through current control switches 1205ab and 1205aa, respectively. Similarly, the signal lines 1202ba and 1202bb are connected to the current source circuit 107b via current control switches 1205bb and 1205ba, respectively.

In the case of FIG. 12, since two signal lines are arranged for one column of pixels, the signal input to the pixels for one row takes 2 × horizontal period, that is, a period twice as long as one horizontal period. Just complete it. Therefore, first, a video signal voltage (precharge voltage) is input over one horizontal period. Then, the video signal current may be input over the next one horizontal period. In addition, since there are two signal lines, when a video signal voltage (precharge voltage) is input to a pixel in one row, a video signal current can be input to a pixel in another row at the same time. I can do it.

The operation is shown in FIGS. 13 and 14, a video signal current is input to the pixels in the first row, and a video signal voltage (precharge voltage) is input to the pixels in the second row. It is assumed that the video signal voltage (precharge voltage) has been input to the signal lines 1202ab and 1202bb before FIG. Next, as shown in FIGS. 15 and 16, the video signal current is input to the pixels in the second row, and the video signal voltage (precharge voltage) is input to the pixels in the third row. Since the video signal voltage (precharge voltage) has already been input to the pixels in the second row, the video signal current can be quickly brought to a steady state.

By repeating such an operation, the video signal current can be accurately written.

13 and 15, video signal voltages (precharge voltages) are input to the pixels 1209ab and 1209bb, but the switches 1210ab and 1210bb arranged in the pixels 1209ab and 1209bb are turned off. Accordingly, the video signal voltage (precharge voltage) is not input to the pixels 1209ab and 1209bb, but the present invention is not limited to this. The input of the video signal voltage (precharge voltage) is mainly to control the potentials of the signal lines 1202aa, 1202ab, 1202ba, and 1202bb. Therefore, the video signal voltage (precharge voltage) is applied to the pixels 1209ab and 1209bb. It may not be input or may be input. When the video signal current is input after the video signal voltage (precharge voltage) is input, either may be used. If the video signal current is not input after the video signal voltage (precharge voltage) is input, the video signal voltage (precharge voltage) is preferably input to the pixels 1209ab and 1209bb.

Note that, as shown in FIGS. 2, 8, 9, and 5 in the first embodiment, the video signal current may be sequentially input after the input of the video signal voltage (precharge voltage) is completed. However, in this case, since it is necessary to supply current to two rows at the same time, it is necessary to arrange a plurality of current source circuits in one column.

Note that the content described in this embodiment corresponds to a part of the structure described in Embodiment 1. Therefore, the contents described in Embodiment Mode 1 can be applied to this embodiment mode.

Therefore, the video voltage signal line 101 and the signal lines 1202aa to 1202bb are connected via the voltage control switches 1204aa to 1204bb, but the present invention is not limited to this. For example, as shown in FIG. 17, voltage storage circuits 1702aa to 1702bb may be arranged between them. By arranging such a circuit, the timing of signal input can be made more flexible.

Further, the present invention is not limited to this, and various modifications are possible as long as the gist thereof is not changed.

Note that the structure described in this embodiment can be combined with the structure in Embodiment 1.

(Embodiment 3)
In the present invention, it is necessary to input a video signal current to the pixel. That is, it is necessary to control the magnitude of current in an analog or digital manner according to image information and input it to the pixel. The video signal current is output from the current source circuit. Therefore, in this embodiment, a configuration example of a current source circuit is shown.

FIG. 18 shows a configuration diagram in a case where a portion related to the current source circuit is described in detail with respect to the configuration diagram of FIG. Similarly, FIG. 19 shows a configuration diagram in the case where a portion related to the current source circuit is described in detail with respect to the configuration diagram of FIG. Although FIG. 1 shows a case where pixels are arranged in 4 rows and 3 columns, FIG. 18 and FIG. 19 assume that pixels are arranged in 4 rows and 2 columns for simplicity. However, the present invention is not limited to this.

18 and 19, the current source circuits 1807a and 1807b are connected to the video current signal line 1801. Then, the video current signal is input to the current source circuits 1807a and 1807b through the video current signal line 1801. As a result, the current source circuits 1807a and 1807b can output video current signals to the signal lines 102a and 102b without being affected by transistor variations.

In the case of FIG. 18, the current source circuits 1807a and 1807b are controlled by the current control lines 1806a and 1806b by the current control shift register 1803. Thus, the timing at which the video current signal is input to the current source circuits 1807a and 1807b is controlled.

As shown in FIG. 18, the voltage control shift register 103 that controls the voltage control switches 104a and 104b and the current control shift register 1803 that controls the current source circuits 1807a and 1807b are arranged separately, so that It becomes possible to control the timing independently. In particular, when a video current signal is input to the current source circuits 1807a and 1807b through the video current signal line 1801, it may take time to complete the input of the signal (to make it steady). In that case, the timing can be optimized by arranging the voltage control shift register 103 and the current control shift register 1803 separately.

In FIG. 10, video voltage signal lines 101a and 101b are arranged. As shown in this figure, a plurality of video voltage signal lines and video current signal lines may be arranged. In FIG. 88, one video voltage signal line (101) and two video current signal lines (1801i, 1801j) are arranged, and the number of video voltage signal lines and the number of video current signal lines are shown. Are not necessarily matched. In such a case, the timing can be optimized by arranging the voltage control shift register 103 and the current control shift register 1803 separately.

As described above, in FIG. 18, the voltage control shift register 103 and the current control shift register 1803 are arranged separately, but the present invention is not limited to this configuration. For example, as shown in FIG. 20, the voltage control shift register 103 and the current control shift register 1803 may be combined into one. For example, in the case of FIG. 20, the voltage control shift register 103 is used to control not only the voltage control switches 104a to 104b but also the current source circuits 1807a and 1807b.

Up to now, the current source circuit has been described using schematic diagrams without describing the internal detailed configuration. Therefore, an example of a circuit configuration inside the current source circuit 1807 is shown. First, FIG. 21 shows a diagram in which the current source circuit portion is extracted from FIG. 18 and FIG. As shown in FIG. 21, the current source circuit 1807 has at least a current input terminal 2102, a timing control terminal 2103, and a current output terminal 2101. In the case of FIG. 18, the current input terminal 2102 is connected to the video current signal line 1801, and current is input therefrom. In the case of FIG. 18, the timing control terminal 2103 is connected to the voltage control shift register 103 and the current control shift register 1803, from which a timing signal is input. In the case of FIG. 18, the current output terminal 2101 is connected to the signal lines 104a and 104b via the current control switches 105a and 105b.

FIG. 22 shows a specific circuit configuration example of the current source circuit 1807 shown in FIG. The switches 2203 and 2204 are turned on, the switch 2205 is turned off, and current is input to the current source transistor 2201 and the storage capacitor 2202 through the current input terminal 2102. When the input of current is completed, that is, when a steady state is reached, an appropriate voltage is stored in the storage capacitor 2202. Thereby, even if the current characteristics of the current source transistor vary, the influence can be reduced. Next, the switches 2203 and 2204 are turned off and the switch 2205 is turned on. Then, the current can be output to the switch 105 through the current output terminal 2101.

If the current source circuit 1807 is configured as shown in FIG. 22, the video current signal input to the current source circuit 1807 through the video current signal line 1801 and the current output terminal 2101 from the current source circuit 1807 are passed. The magnitudes of the video current signals output in the same manner are approximately equal. This depends on the circuit configuration. That is, since the transistor to which current is input through the video current signal line 1801 and the transistor to output current through the current output terminal 2101 are the same, the magnitudes of the currents are approximately equal.

Therefore, when the current source circuit 1807 is configured as shown in FIG. 23, the magnitude of the current is changed by changing the ratio between the channel width W and the channel length L in the current source transistor 2301 and the mirror transistor 2306. I can do it. In this case, the magnitude of the video current signal input to the current source circuit 1807 through the video current signal line 1801 and the video current signal output from the current source circuit 1807 through the current output terminal 2101 is as follows. , Become a proportional relationship. Reference numeral 2302 denotes a storage capacitor, 2303 and 2304 denote switches, and 105 denotes a switch.

Similarly, when the current source circuit 1807 is configured as shown in FIG. 24, the switches 2403 and 2404 are turned on, and the current is input to the current source transistor 2401 and the storage capacitor 2402 through the current input terminal 2102. When the switches 2403 and 2404 are turned off and the current source transistor 2401 and the multi-transistor 2405 operate as multi-gate transistors and output current through the current output terminal 2101, the magnitude of the current is Can be changed. Also in this case, the magnitude of the video current signal input to the current source circuit 1807 through the video current signal line 1801 and the video current signal output from the current source circuit 1807 through the current output terminal 2101 is as follows. , Become a proportional relationship.

Similarly, if the current source circuit 1807 is configured as shown in FIG. 25, it is possible to control whether the current source transistor 2501 and the multi-transistor 2506 operate as multi-gate transistors by controlling the switch 2507. . In this case, the video current signal input to the current source circuit 1807 through the video current signal line 1801 and the current source circuit 1807 to the switch 105 through the current output terminal 2101 are output to the switch 105 according to the ON / OFF timing of the switch 2507. The magnitude of the video current signal may be proportional or may be approximately equal.

  Note that the operation of the current source circuit as shown in FIG. 25 is described in Japanese Patent Application Nos. 2002-380252 and 2003-055018, and the contents thereof can be combined with this application. . Reference numerals 2503, 2504, 2505, and 105 denote switches.

  22 to 25, the current flowing through the current input terminal 2102 and the current flowing through the current output terminal 2101 are flowing in the current source circuit, but the present invention is not limited to this. A current may flow in the opposite direction between the current input terminal 2102 and the current output terminal 2101. An example in that case is shown in FIG. In the case of FIG. 26, the current flowing through the current output terminal 2101 flows toward the current source circuit, but the current flowing through the current input terminal 2102 flows from the current source circuit toward another circuit. Yes. Note that 2601 is a transistor, 2203, 2605, 2606, and 2607 are switches.

  In FIGS. 22 to 26, the polarity of the transistor operating as a current source is an N-channel type, but the present invention is not limited to this. As an example, FIG. 27 shows a case where the transistor polarity is P-channel type with respect to the configuration of FIG. Note that reference numeral 2701 denotes a P-channel transistor, 2702 denotes a storage capacitor, and 2703, 2704, and 2705 denote switches. 23 to 26, the transistor polarity can be changed by applying the same concept.

  In FIGS. 22 to 27, a current flows in the current source circuit, but the present invention is not limited to this. Even when the direction of the current is changed, it can be easily deformed. As an example, FIG. 28 shows a case where the direction of current flow is reversed with respect to the configuration of FIG. Note that 2801 is a P-channel transistor, 2802 is a storage capacitor, and 2803, 2804, and 2805 are switches. In this manner, by reversing the polarity of the transistor operating as a current source, it is possible to cope with it without changing the circuit connection relationship.

  22 to 28, when operating as a multi-gate transistor, if one multi-gate transistor is counted, only one transistor is operating as a current source in the current source circuit. However, the present invention is not limited to this, and a plurality of transistors may be provided. As an example, FIG. 29 shows a case where there are two transistors operating as current sources in the configuration of FIG. By controlling the control line 2901, as shown in FIG. 30, when a current is input from the video current signal line 1801 to the current source transistor 2201b and a current is output from the current source transistor 2201a, FIG. As shown, the current source transistor 2201a can be switched between inputting a current from the video current signal line 1801 and outputting a current from the current source transistor 2201b. As described above, by arranging a plurality of current source transistors in the current source circuit, the operation of inputting current from the video current signal line 1801 and the operation of outputting current through the current output terminal 2101 are simultaneously performed. Can be done.

  Note that in the case where a plurality of current source transistors are arranged in the current source circuit, the operation is switched using the control line 2901 in FIG. 29, but the present invention is not limited to this. For example, a current source transistor arbitrarily selected from a plurality of current source transistors may be used to output the total current through the current output terminal 2101.

FIG. 32 shows an example when there are two current source transistors in the configuration of FIG. In FIG. 32, the current source transistor 3201a receives a current from the video current signal line 1801j. On the other hand, the current source transistor 3201b receives a current from the video current signal line 1801i. Therefore, the current source transistor 3201a and the current source transistor 3201b can output currents having different sizes. Whether or not to output the current through the current output terminal 2101 is controlled using the switches 3202a and 3202b. Further, if the on / off of the switches 3202a and 3202b is controlled using a video signal, the magnitude of the current output through the current output terminal 2101 can be set to a magnitude corresponding to the video signal. For example, if the current value output from the current source transistor 3201a is I0 and the current value output from the current source transistor 3201b is I0 × 2, a 2-bit gradation can be expressed. If the number of current source transistors is further increased and the magnitude of each current is raised to a power of 2, it is possible to express a multi-bit gradation.

  In FIG. 29, the current source transistors are arranged in parallel, but the present invention is not limited to this. FIG. 33 shows an example in which current source transistors are arranged in series. As for the operation, by controlling the control line 3301, as shown in FIG. 34, the current is input from the video current signal line 1801 to the current source transistor 2201c and the current is output from the current source transistor 2201d. As shown in FIG. 35, a current may be input from the current source transistor 2201c to the current source transistor 2201d. By arranging in this way, the operation of inputting current from the video current signal line 1801 and the operation of outputting current through the current output terminal 2101 can be performed simultaneously.

  In addition, although the current source circuit of various structures was shown to FIGS. 22-33, it is not limited to this. With respect to the basic configuration, the number, polarity and arrangement of the current source transistors, the direction of current flow, and the like, further configurations can be used by combining the configurations or combining the concepts in the configurations. That is, any configuration can be used as long as it operates as a current source circuit.

  It should be noted that the arrangement of the current source circuit shown in FIGS. 22 to 33 can be easily modified with respect to the arrangement and number of switches in each part, the connection relations associated therewith, and the like. In other words, as long as the current source circuit operates normally, there can be any number of switches, and multiple switches can be combined into one, or the connection relationship can be modified to add or delete switches. Also good.

  Regarding the configuration of the current source circuit, International Publication No. 03/038793, International Publication No. 03/038794, International Publication No. 03/038795, International Publication No. 03/038796, International Publication No. 03 / 038797 pamphlet, the contents of which can be applied to the present invention or combined with the present invention.

Note that the content described in this embodiment corresponds to a part of the configuration described in Embodiments 1 and 2 in detail. Therefore, the contents described in Embodiments 1 and 2 can be applied to this embodiment.

Further, the present invention is not limited to this, and various modifications are possible as long as the gist thereof is not changed.

Note that the structure described in this embodiment can be implemented in combination with the structure in Embodiments 1 and 2.

(Embodiment 4)
As shown in FIG. 18 and the like, it is necessary to supply a video signal voltage having a magnitude corresponding to the display of the pixel and a video signal current having a magnitude corresponding to the display of the pixel. That is, the video signal voltage and the video signal current have a magnitude related to each other. Therefore, in this embodiment, a circuit for supplying a video signal voltage and a video signal current is described.

  First, the overall configuration is shown in FIG. A signal is input from the original signal input terminal 5012 to the voltage / current supply circuit 5011. In response to the signal, a signal current is output from the current output terminal 5013 and a signal voltage is output from the voltage output terminal 5014. The current output terminal 5013 and the voltage output terminal 5014 are connected to the input terminal 5022 of the setting target circuit 5021 via the switches 5001 and 5002. Note that the circuit to be set 5021 indicates a circuit in which a current is set by the voltage / current supply circuit 5011.

  The set circuit 5021 is precharged using the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 and then uses the signal current supplied from the current output terminal 5013 of the voltage / current supply circuit 5011. Current is set. As a result, the circuit to be set 5021 can supply an accurate current almost without being affected by variations in current characteristics of transistors constituting the circuit.

  Note that the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 is the signal voltage supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 to reach a steady state, that is, the signal writing. The voltage value is almost the same as when the is completed. Therefore, by supplying a signal voltage from the voltage output terminal 5014 and precharging it, when a signal current is subsequently supplied from the current output terminal 5013 of the voltage / current supply circuit 5011, a steady state can be quickly established.

  That is, the magnitude of the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 and the magnitude of the signal current supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 are related to each other. ing.

  Note that when current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 to the input terminal 5022 of the set circuit 5021, it is necessary to pay attention to the direction of the current. In other words, when a current flows from the voltage / current supply circuit 5011 to the outside (referred to as a discharge type), the circuit to be set 5021 allows a current to flow in (referred to as a suction type). It is necessary to keep. In this case, the voltage / current supply circuit 5011 has a higher potential, and a current flows from the voltage / current supply circuit 5011 to the set circuit 5021. In addition, when current flows in from the voltage / current supply circuit 5011 (in the case of a suction type), the set circuit 5021 needs to allow current to flow outward (in the case of a discharge type). In this case, the voltage / current supply circuit 5011 has a lower potential, and a current flows from the set circuit 5021 toward the voltage / current supply circuit 5011.

  When both the voltage / current supply circuit 5011 and the circuit to be set 5021 are of the suction type or the discharge type, the current flow is not normal, so that they do not operate normally. Therefore, it is necessary to adjust whether the voltage / current supply circuit 5011 and the set circuit 5021 are the suction type or the discharge type.

  First, the configuration of the circuit to be set 5021 will be briefly described. 37 and 38 show configuration examples of the set circuit 5021 in the case of the discharge type. FIG. 37 shows the case where the transistor 3701 to operate as a current source is a P-channel type, and FIG. 38 shows the case of an N-channel type.

  Note that the capacitor elements 3703 and 3803 function to hold a gate-source voltage of the transistors 3701 and 3801. However, it can be omitted depending on the gate capacitance of the transistors 3701 and 3801.

  Note that in FIG. 38, the source terminal of the transistor 3801 is connected to the input terminal 5022 of the circuit to be set 5021 and is not connected to the constant potential line. Therefore, the source potential of the transistor 3801 may change depending on the operating state. Therefore, the terminal 3805 is preferably connected to the source terminal of the transistor 3801 so that the gate-source voltage of the transistor 3801 does not change even when the source potential of the transistor 3801 changes. Further, the gate terminal and the drain terminal of the transistor 3801 may be connected.

  Note that the transistors of the circuit to be set 5021 are set so that a predetermined current can be supplied by using a signal supplied from the voltage / current supply circuit 5011, that is, the current is set. Then, the transistor of the circuit to be set 5021 supplies a predetermined current to another circuit or element and operates as a current source. However, in FIGS. 37 and 38, for the sake of simplicity, other circuits and elements that supply current after the transistors (transistors 3701 and 3801) of the circuit to be set 5021 have been set for current are not shown.

In addition, a switch is often provided in order to hold the charge of the capacitor elements 3703 and 3803, but in FIGS. 37 and 38, it is not shown for simplicity.

That is, FIGS. 37 and 38 show the configuration of the circuit to be set 5021 in a state where a signal is supplied from the voltage / current supply circuit 5011 and the current is set for simplicity.

  39 and 40 show a configuration example of the set circuit 5021 in the case of the suction type. FIG. 40 shows the case where the transistor 4001 to be operated as a current source is a P-channel type, and FIG. 39 shows the case where the transistor 3901 is an N-channel type, which is considered in the same manner as FIGS. I can do it.

  Next, an example of the voltage / current supply circuit 5011 in FIG. 36 is shown. Also in the case of the voltage / current supply circuit 5011, the configuration of the portion that outputs current varies depending on whether it is a suction type or a discharge type. In addition, the portion that outputs the voltage varies depending on the configuration of the circuit to be set 5021. In other words, the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 is the voltage when the signal current is supplied from the current output terminal 5013 to the circuit to be set 5021 and becomes a steady state, that is, the signal is written. Needs to be approximately equal to the voltage at the completion of. Therefore, the circuit 5021 to be set is a suction type or a discharge type, the polarity of the transistor is an N-channel type or a P-channel type, the ratio of the channel width W to the channel length L, and the like. It is necessary to control the magnitude of the signal voltage supplied from the voltage output terminal 5014.

  Further, a voltage or a current may be supplied to the original signal input terminal 5012 of the voltage / current supply circuit 5011 as a signal. A signal current is supplied from a current output terminal 5013 and a signal voltage is supplied from a voltage output terminal 5014 based on a signal supplied therefrom.

As an example, a voltage / current supply circuit 5011 having the configuration of FIG. 39 in which the circuit to be set 5021 is a suction type and the transistor 3901 is an N-channel type will be described. In addition, although the case where it has the structure of FIG. 39 is shown here, you may have the structure of FIG. FIG. 41 shows the configuration.

A voltage is input from the original signal input terminal 5012. Since the original signal input terminal 5012 is connected to the gate terminal of the transistor 4101, the gate-source voltage of the transistor 4101 changes depending on the potential of the original signal input terminal 5012, and current flowing from the terminal 4102 to the transistor 4101 The amount changes. Since the transistor 4103 is connected in series with the transistor 4101, the same amount of current flows as the transistor 4101. A gate terminal and a drain terminal of the transistor 4103 are connected to each other, and a gate terminal of the transistor 4105 is also connected to the connected portion. As shown in FIG. 41, the source terminal or the drain terminal of the transistor 4103 and the transistor 4105 are connected in series through the terminal 4104. Therefore, the current output terminal 5013 outputs a current according to the ratio of the ratio W11 / L11 of the channel width W and the channel length L of the transistor 4105 and the ratio W12 / L12 of the channel width W and the channel length L of the transistor 4103. Is done. Here, (W12 / L12) = α × (W11 / L11). Then, from the current output terminal 5013, a current that is α times the current flowing through the transistor 4101 (transistor 4103) flows.

  Then, the gate potential of the transistor 4101 is output to the voltage output terminal 5014. Note that an amplifier circuit such as a voltage follower circuit may be disposed between the original signal input terminal 5012 and the voltage output terminal 5014.

  Therefore, the current output from the current output terminal 5013 flows through the transistor 3901 in FIG. Here, if the ratio W13 / L13 of the channel width W and the channel length L of the transistor 4101 and the ratio W21 / L21 of the channel width W and the channel length L of the transistor 3901 are adjusted, the voltage of the voltage / current supply circuit 5011 The signal voltage supplied from the output terminal 5014 is approximately equal to the voltage when the signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 to reach a steady state, that is, when the signal writing is completed. Value. That is, (W21 / L21) = α × (W13 / L13) may be set. Then, the gate-source voltage of the transistor 4101 and the gate-source voltage of the transistor 3901 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  In FIG. 41, the original signal input terminal 5012 is connected to the gate terminal of the N-channel transistor. Next, FIG. 42 shows a configuration in the case where the original signal input terminal 5012 is connected to the gate terminal of a P-channel transistor. Since the original signal input terminal 5012 is connected to the gate terminal of the transistor 5101, the voltage between the gate and source of the transistor 5101 changes depending on the potential of the original signal input terminal 5012, and the amount of current flowing through the transistor 5101 changes. The current is output from the current output terminal 5013. On the other hand, the gate terminal of the transistor 6401 is connected to the gate terminal of the transistor 5101. Here, the ratio W31 / L31 of the channel width W and the channel length L of the transistor 5101 and the ratio W32 / L32 of the channel width W and the channel length L of the transistor 6401 are set, and (W32 / L32) = β × (W31 / L31) Then, a current that is β times the current flowing through the transistor 5101 flows through the transistor 6401 and the transistor 6402.

  Then, the gate potential of the transistor 6402 is output to the voltage output terminal 5014 through the amplifier circuit 5301. Note that the amplifier circuit 5301 is a circuit that outputs a potential substantially equal to the input potential, and is preferably a voltage follower circuit or the like. However, the present invention is not limited to this, and a function for converting impedance may be performed. Note that in the case where a sufficiently large amount of charge is supplied from the gate terminal or the drain terminal of the transistor 6402 and impedance conversion is not necessary, the amplifier circuit 5301 may be omitted.

Here, if the ratio W33 / L33 of the channel width W and the channel length L of the transistor 6402 and the ratio W21 / L21 of the channel width W and the channel length L of the transistor 3901 in FIG. When the signal voltage supplied from the voltage output terminal 5014 of 5011 is supplied with the signal current from the current output terminal 5013 of the voltage / current supply circuit 5011 to be in a steady state, that is, when the signal writing is completed, The voltage values are approximately equal. That is, (W21 / L21) = (W33 / L33) / β may be set. Then, the gate-source voltage of the transistor 6402 and the gate-source voltage of the transistor 3901 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  41 and 42, a voltage is input to the original signal input terminal 5012 as a signal. Next, a configuration in the case where a current is input to the original signal input terminal 5012 is shown.

FIG. 43 shows the case where a current is input to the P-channel transistor 4301. FIG. 43 is obtained by adding a P-channel transistor 4301 to the configuration of FIG. That is, in FIG. 42, the gate potential of the transistor 5101 is directly controlled through the original signal input terminal 5012. On the other hand, in FIG. 43, the gate potential of the transistor 5101 is controlled by passing a current through the P-channel transistor 4301. Since the other portions are the same as those in FIG. 42, the description thereof is omitted.

Next, FIG. 44 shows a case where current is input to the N-channel transistor 4401. 44 is obtained by adding an N-channel transistor 4401 to the configuration of FIG. In the configuration shown in FIG. 41, the gate potential of the transistor 4101 is directly controlled via the original signal input terminal 5012.
On the other hand, in FIG. 44, the gate potential of the transistor 4101 is controlled by supplying a current to the N-channel transistor 4401. In other words, the gate terminal of the transistor 4101 is connected to the gate terminal of the transistor 4401, and the gate terminal of the transistor 4103 is connected to the gate terminal of the transistor 4105. Accordingly, current corresponding to the current flowing through the transistor 4401 flows through the transistor 4101, the transistor 4103, and the transistor 4105.

Here, the ratio W51 / L51 between the channel width W and the channel length L of the transistor 4401, the ratio W52 / L52 between the channel width W and the channel length L of the transistor 4101, and the ratio W53 / L53 between the channel width W and the channel length L of the transistor 4103. As a ratio W54 / L54 between the channel width W and the channel length L of the transistor 4105, (W51 / L51) = (W52 / L52) / ε and (W53 / L53) = (W54 / L54) / ζ. Then, a current ε times the current flowing through the transistor 4401 flows through the transistors 4101 and 4103. In addition, a current ζ times as large as the current flowing through the transistor 4103 flows through the transistor 4105.

  Then, the gate potential of the transistor 4401 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

Here, the ratio W51 / L51 between the channel width W and the channel length L of the transistor 4401, the ratio W52 / L52 between the channel width W and the channel length L of the transistor 4101, and the ratio W53 / L53 between the channel width W and the channel length L of the transistor 4103. By adjusting the ratio W54 / L54 of the channel width W and the channel length L of the transistor 4105 and the ratio W21 / L21 of the channel width W and the channel length L of the transistor 3901 in FIG. The signal voltage supplied from the voltage output terminal 5014 is approximately equal to that when the signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 to reach a steady state, that is, when signal writing is completed. It becomes a voltage value. That is, (W21 / L21) = (W51 / L51) × ε × ζ may be satisfied. Then, the gate-source voltage of the transistor 4401 and the gate-source voltage of the transistor 3901 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  Next, the voltage / current supply circuit 5011 in the case of the configuration in FIG. 40 in which the circuit to be set 5021 is a suction type and the transistor 4001 is a P-channel type will be described. Note that for simplicity, terminals 3902 and 3904 are connected in FIG. 40, and the terminal 4005 is connected to the input terminal 5022 of the circuit to be set 5021 (the source terminal of the transistor 4001).

  In this case, the source terminal of the transistor 4001 of the circuit to be set 5021 is connected to the input terminal 5022 of the circuit to be set 5021. Accordingly, the source potential of the transistor 4001 changes depending on the state. That is, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 and a steady state is obtained, that is, when signal writing is completed, the potential of the input terminal 5022 of the circuit to be set 5021 is changed to the transistor This is the potential when the source terminal 4001 is in a steady state. Therefore, the magnitude of the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 needs to be the magnitude of the source potential of the transistor 4001 when the steady state is reached.

  FIG. 45 shows a configuration in the case where a voltage is input to the original signal input terminal 5012 and the original signal input terminal 5012 is connected to the gate terminal of the P-channel transistor 5101.

  FIG. 45 corresponds to the transistor 6402 in FIG. 42 that is changed from an N-channel transistor to a P-channel transistor 4502. That is, the gate terminal of the transistor 5101 is connected to the gate terminal of the transistor 6401. Accordingly, a current corresponding to the current flowing through the transistor 5101 flows through the transistor 6401 and the transistor 4502. Here, the ratio W61 / L61 of the channel width W to the channel length L of the transistor 5101, the ratio W62 / L62 of the channel width W to the channel length L of the transistor 6401, and the ratio W63 / L63 of the channel width W to the channel length L of the transistor 4502. (W61 / L61) = (W62 / L62) / η. Then, a current that is η times the current flowing through the transistor 5101 flows through the transistor 6401.

  Then, the source potential of the transistor 4502 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

Here, the ratio W61 / L61 of the channel width W to the channel length L of the transistor 5101, the ratio W62 / L62 of the channel width W to the channel length L of the transistor 6401, and the ratio W63 / L63 of the channel width W to the channel length L of the transistor 4502. If the ratio W22 / L22 of the channel width W and the channel length L of the transistor 4001 in FIG. 40 is adjusted, the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 becomes the voltage / current supply circuit. When the signal current is supplied from the current output terminal 5013 of 5011 and a steady state is obtained, that is, when the signal writing is completed, the voltage value is substantially equal. That is, (W22 / L22) = (W63 / L63) / η may be set. Then, the gate-source voltage of the transistor 4502 and the gate-source voltage of the transistor 4001 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  Next, FIG. 46 illustrates a configuration in which a voltage is input to the original signal input terminal 5012 and the original signal input terminal 5012 is connected to the gate terminal of the N-channel transistor 4101.

  46 corresponds to a configuration in which transistors 4601 and 4602 are added to the configuration of FIG. That is, the gate terminal of the transistor 4103 is connected to the gate terminal of the transistor 4601 and the gate terminal of the transistor 4105. Therefore, current corresponding to the current flowing through the transistor 4101 flows through the transistor 4601 and the transistor 4105. Here, the ratio W71 / L71 of the channel width W to the channel length L of the transistor 4103, the ratio W72 / L72 of the channel width W to the channel length L of the transistor 4601, and the ratio W73 / L73 of the channel width W to the channel length L of the transistor 4105. (W71 / L71) = (W72 / L72) / θ = (W73 / L73) / ι. Then, a current θ times the current flowing through the transistor 4103 flows through the transistor 4601, and a current ι times the current flowing through the transistor 4103 flows through the transistor 4105.

  Then, the source potential of the transistor 4602 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

  Here, the ratio W71 / L71 of the channel width W to the channel length L of the transistor 4103, the ratio W72 / L72 of the channel width W to the channel length L of the transistor 4601, and the ratio W73 / L73 of the channel width W to the channel length L of the transistor 4105. If the ratio W74 / L74 of the channel width W and the channel length L of the transistor 4602 and the ratio W22 / L22 of the channel width W and the channel length L of the transistor 4001 in FIG. 40 are adjusted, the voltage / current supply circuit 5011 The signal voltage supplied from the voltage output terminal 5014 is approximately equal to that when the signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 to reach a steady state, that is, when signal writing is completed. It becomes a voltage value. That is, (W22 / L22) = (W74 / L74) × ι / θ may be set. Then, the gate-source voltage of the transistor 4602 and the gate-source voltage of the transistor 4001 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  47 and 48 show a configuration in the case where a current is input to the original signal input terminal 5012. FIG. 47 corresponds to the transistor 4701 added to FIG. 45 so that a current can be input, and FIG. 48 corresponds to the transistor 4801 added to FIG. 46 so that a current can be input. To do.

  As described above, FIGS. 41 to 48 have described the case where the voltage / current supply circuit 5011 is the discharge type. However, when the set circuit 5021 is a discharge type as shown in FIGS. 37 and 38, the voltage / current supply circuit 5011 needs to be a suction type. However, when changing from the discharge type configuration to the suction type configuration, it is only necessary to change the polarity of the transistor. For example, FIG. 49 shows a configuration when FIG. 41 is changed to the suction type. In this way, the polarity of each transistor may be reversed and the potential of each wiring may be changed.

(Embodiment 5)
In the fourth embodiment, the voltage / current supply circuit 5011 and the set circuit 5021 are connected as they are. In this embodiment mode, a case where a current storage circuit 5031 is inserted between the voltage / current supply circuit 5011 and the set circuit 5021 as shown in FIG. 50 will be described.

  As shown in FIG. 50, a signal current is output from the current output terminal 5013 of the voltage / current supply circuit 5011 to the current storage circuit 5031, current setting is performed in the current storage circuit 5031, and the current value is stored. At that time, a signal voltage is output from the voltage output terminal 5014 of the voltage / current supply circuit 5011 to the set circuit 5021. Therefore, precharge is performed in the circuit 5021 to be set. Thereafter, a signal current is output from the current storage circuit 5031 to the set circuit 5021, and the current is set in the set circuit 5021. Note that the magnitude of the current output from the current storage circuit 5031 to the set circuit 5021 is proportional to the magnitude of the current output from the current output terminal 5013 of the voltage / current supply circuit 5011 to the current storage circuit 5031. Alternatively, depending on the configuration of the current storage circuit 5031, the current storage circuits 5031 are approximately equal.

  When the circuit configuration for supplying the video signal voltage and the video signal current shown in FIG. 36 is used, which of the voltage / current supply circuit 5011 and the set circuit 5021 is a suction type and which is a discharge type. It was necessary to adjust. In the case of the configuration of FIG. 50, it is necessary to consider not only the types of the voltage / current supply circuit 5011 and the set circuit 5021 but also the type of the current storage circuit 5031.

First, the current storage circuit 5031 is the same when a current is input from the current output terminal 5013 of the voltage / current supply circuit 5011 to the current storage circuit 5031 and when a current is output from the current storage circuit 5031 to the set circuit 5021. Consider the case of type. For example, when the current storage circuit 5031 is a discharge type, both the voltage / current supply circuit 5011 and the set circuit 5021 need to be a suction type. Conversely, when the current storage circuit 5031 is a suction type, both the voltage / current supply circuit 5011 and the set circuit 5021 need to be a discharge type. That is, the voltage / current supply circuit 5011 and the circuit to be set 5021 need to be the same type.

  Next, when the current is input from the current output terminal 5013 of the voltage / current supply circuit 5011 to the current storage circuit 5031 and when the current is output from the current storage circuit 5031 to the set circuit 5021, the current storage circuit 5031 Consider the case of the opposite type. For example, in the case of a discharge type when input from the voltage / current supply circuit 5011 to the current storage circuit 5031 and a suction type when outputting current from the current storage circuit 5031 to the set circuit 5021, the voltage / current supply circuit 5011 is a suction type. The set circuit 5021 needs to be a discharge type. Conversely, in the case of the suction type when input from the voltage / current supply circuit 5011 to the current storage circuit 5031 and the discharge type when outputting current from the current storage circuit 5031 to the set circuit 5021, the voltage / current supply circuit 5011 discharges. Type, and the circuit to be set 5021 needs to be a suction type. In other words, the voltage / current supply circuit 5011 and the circuit to be set 5021 need to be reversed.

First, the configuration of the voltage / current supply circuit 5011 will be described in the case where both the voltage / current supply circuit 5011 and the set circuit 5021 are discharge types. Note that the magnitude of current when input from the voltage / current supply circuit 5011 to the current storage circuit 5031 is I ₁ , and the magnitude of current when output from the current storage circuit 5031 to the set circuit 5021 is I ₂ . Suppose that I ₂ = I ₁ × κ.

First, it is assumed that the circuit to be set 5021 is a discharge type, and a P-channel transistor 3701 is used as in the configuration of FIG. FIG. 51 shows an example of the configuration of the voltage / current supply circuit 5011 in that case.

In FIG. 51, a voltage is input from an original signal input terminal 5012. Since the original signal input terminal 5012 is connected to the gate terminal of the transistor 5101, the voltage between the gate and the source of the transistor 5101 changes depending on the potential of the original signal input terminal 5012, and the amount of current flowing through the transistor 5101 changes. To do.

  Then, the current output from the current storage circuit 5031 flows through the transistor 3701 of the circuit to be set 5021. The current output from the current storage circuit 5031 to the set circuit 5021 is κ times larger than the current input from the voltage / current supply circuit 5011 to the current storage circuit 5031.

  Then, the gate potential of the transistor 5101 is output to the voltage output terminal 5014. Note that an amplifier circuit such as a voltage follower circuit may be disposed between the original signal input terminal 5012 and the voltage output terminal 5014.

Here, if the ratio W81 / L82 of the channel width W and channel length L of the transistor 5101 and the ratio W23 / L23 of the channel width W and channel length L of the transistor 3701 are adjusted, the voltage of the voltage / current supply circuit 5011 The voltage value of the signal supplied from the output terminal 5014 is approximately equal to that when the signal current is supplied from the current storage circuit 5031 to the set circuit 5021 to reach a steady state, that is, when the signal writing is completed. become. That is, (W23 / L23) = κ × (W82 / L82) may be set. Then, the gate-source voltage of the transistor 5101 and the gate-source voltage of the transistor 3701 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, after the precharge, when a signal current is supplied from the current output terminal 5033 of the current storage circuit 5031, a steady state can be quickly achieved.

  Next, in FIG. 51, the original signal input terminal 5012 is connected to the gate terminal of the P-channel transistor. However, the original signal input terminal 5012 is connected to the gate terminal of the N-channel transistor. Is shown in FIG.

In FIG. 52, since the original signal input terminal 5012 is connected to the gate terminal of the transistor 4101, the voltage between the gate and the source of the transistor 4101 varies depending on the potential of the original signal input terminal 5012. The amount of current flowing changes. Accordingly, current corresponding to the current flowing through the transistor 4101 flows through the transistor 4103 and the transistor 4105. On the other hand, the gate terminal of the transistor 4105 is connected to the gate terminal of the transistor 4103. In addition, the source terminal or the drain terminal of the transistor 4103 and the transistor 4105 are connected by a terminal 4104. Here, the ratio W91 / L91 of the channel width W and the channel length L of the transistor 4103 and the ratio W92 / L92 of the channel width W and the channel length L of the transistor 4105 are given by (W92 / L92) = λ × (W92 / L92) Then, a current that is λ times the current flowing through the transistor 4101 and the transistor 4103 flows through the transistor 4105.

  Then, the gate potential of the transistor 4105 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

Here, the ratio W91 / L91 of the channel width W and the channel length L of the transistor 4103, the ratio W92 / L92 of the channel width W and the channel length L of the transistor 4105, the channel width W and the channel length L of the transistor 3901 in FIG. If the ratio W23 / L23 is adjusted, the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011, and the steady state When this is the case, that is, when the signal writing is completed, the voltage value is substantially equal. That is, (W23 / L23) = λ × (W91 / L91) may be set. Then, the gate-source voltage of the transistor 4105 and the gate-source voltage of the transistor 3701 are approximately equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  51 and 52, a voltage is input to the original signal input terminal 5012 as a signal. Next, a configuration in the case where a current is input to the original signal input terminal 5012 is shown.

FIG. 53 shows the case where a current is input to the P-channel transistor 5303. 53 is obtained by adding a P-channel transistor 5303 to the configuration of FIG. That is, in FIG. 51, the gate potential of the transistor 5101 is directly controlled via the original signal input terminal 5012. On the other hand, in FIG. 53, the gate potential of the transistor 5101 is controlled by passing a current through the P-channel transistor 5303. Other parts are the same as those in FIG. 51, and a description thereof will be omitted. In FIG. 53, reference numeral 5102 denotes a wiring connecting the transistor 5101 and the transistor 5303.

  FIG. 53 shows the case where current is input from the original signal input terminal 5012 to the P-channel transistor 5303. Next, FIG. 54 shows a case where current is input to the N-channel transistor 5401.

FIG. 54 is obtained by adding an N-channel transistor 5401 to the structure of FIG. In FIG. 52, the gate potential of the transistor 4101 is directly controlled via the original signal input terminal 5012. On the other hand, in FIG. 53, the gate potential of the transistor 4101 is controlled by passing a current through the amplifier circuit 5301. That is, the gate terminal of the transistor 4101 is connected to the gate terminal of the transistor 5301. Accordingly, current corresponding to the current flowing through the transistor 5401 flows through the transistor 4101, the transistor 4103, and the transistor 4105. The other parts are the same as those in FIG. 53, and a description thereof will be omitted.

  Next, the voltage / current supply circuit 5011 in the case of the configuration in FIG. 38 in which the circuit to be set 5021 is a discharge type and the transistor 3801 is an N-channel type will be described. Note that for simplicity, terminals 3702 and 3704 are connected in FIG. 38, and the terminal 3805 is connected to the input terminal 5022 of the circuit to be set 5021 (the source terminal of the transistor 3801).

  In this case, the source terminal of the transistor 3801 of the circuit to be set 5021 is connected to the input terminal 5022 of the circuit to be set 5021. Accordingly, the source potential of the transistor 3801 changes depending on the state. That is, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 and a steady state is obtained, that is, when signal writing is completed, the potential of the input terminal 5022 of the circuit to be set 5021 is changed to the transistor This is the potential when the source terminal 3801 is in a steady state. Therefore, the magnitude of the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 needs to be the magnitude of the source potential of the transistor 3801 when the steady state is reached.

  Therefore, FIG. 55 shows a configuration in which a voltage is input to the original signal input terminal 5012 and the original signal input terminal 5012 is connected to the gate terminal of the P-channel transistor 5101.

  In FIG. 55, the gate terminal of the transistor 5101 is connected to the gate terminal of the transistor 5503, and the gate terminal of the transistor 5506 is connected to the gate terminal of the transistor 5508. Further, the transistors 5101, 5503, and 5509 are connected by a wiring 5504 as shown in FIG. 55, and the transistors 5508 and 5506 are connected by a wiring 5507 as shown in FIG. Accordingly, current corresponding to the current flowing through the transistor 5101 flows through the transistor 5503, the transistor 5506, and the transistor 5508. Here, the ratio W101 / L101 of the channel width W and the channel length L of the transistor 5101, the ratio W102 / L102 of the channel width W and the channel length L of the transistor 5503, and the ratio W103 / L103 of the channel width W and the channel length L of the transistor 5506. As a ratio W104 / L104 of the channel width W and the channel length L of the transistor 5508, (W101 / L101) = (W102 / L102) / μ and (W103 / L103) = (W104 / L104) / ν. Then, a current that is (μ × ν) times as large as the current flowing through the transistor 5101 flows through the transistor 5509.

  Then, the source potential of the transistor 5509 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

Here, the gate terminal of the transistor 5101 is connected to the gate terminal of the transistor 5503, and the gate terminal of the transistor 5506 is connected to the gate terminal of the transistor 5508. Accordingly, current corresponding to the current flowing through the transistor 5101 flows through the transistor 5503, the transistor 5506, and the transistor 5508. Here, the ratio W101 / L101 of the channel width W and the channel length L of the transistor 5101, the ratio W102 / L102 of the channel width W and the channel length L of the transistor 5503, and the ratio W103 / L103 of the channel width W and the channel length L of the transistor 5506. The ratio W104 / L104 of the channel width W and channel length L of the transistor 5508, the ratio W105 / L105 of the channel width W and channel length L of the transistor 5509, and the ratio W23 of the channel width W and channel length L of the transistor 3801 in FIG. / L23 is adjusted, the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011, and the steady state is obtained. That is, the signal writing And when the body has been completed, it becomes substantially equal to the voltage value. That is, (W23 / L23) = (W105 / L105) / (μ × ν) may be satisfied. Then, the gate-source voltage of the transistor 5509 and the gate-source voltage of the transistor 3801 are substantially equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  Next, FIG. 56 illustrates a structure in which a voltage is input to the original signal input terminal 5012 and the original signal input terminal 5012 is connected to the gate terminal of the N-channel transistor 4101.

  In FIG. 56, the gate terminal of the transistor 4103 is connected to the gate terminal of the transistor 4105, and the gate terminal of the transistor 5601 is connected to the gate terminal of the transistor 4101. The transistors 4103, 4105, and 5602 are connected to each other through a terminal 4104, and the transistor 4101 and the transistor 5601 are connected to each other through a terminal 4102. Therefore, current corresponding to the current flowing through the transistor 4101 flows through the transistor 4103, the transistor 4805, and the transistor 5601. Here, the ratio W111 / L111 of the channel width W and the channel length L of the transistor 4101, the ratio W112 / L112 of the channel width W and the channel length L of the transistor 4103, and the ratio W113 / L113 of the channel width W and the channel length L of the transistor 4105. As a ratio W114 / L114 of the channel width W and the channel length L of the transistor 5601, (W112 / L112) = (W113 / L113) / ξ and (W111 / L111) = (W115 / L115) / π. Then, a current ξ times the current flowing through the transistor 4103 and the transistor 4101 flows through the transistor 4805, and a current π times the current flowing through the transistor 4103 flows through the transistor 5601 and the transistor 5602.

  Then, the source potential of the transistor 5602 is output to the voltage output terminal 5014 through the amplifier circuit 5301. However, the present invention is not limited to this, and the amplifier circuit 5301 may be omitted when there is no need to perform impedance conversion.

Here, the ratio W111 / L111 of the channel width W and the channel length L of the transistor 4101, the ratio W112 / L112 of the channel width W and the channel length L of the transistor 4103, and the ratio W113 / L113 of the channel width W and the channel length L of the transistor 4105. 38, the ratio W114 / L114 of the channel width W and the channel length L of the transistor 5601, the ratio W115 / L115 of the channel width W and the channel length L of the transistor 5602, and the ratio W23 of the channel width W and the channel length L of the transistor 3801 in FIG. / L23 is adjusted, the signal voltage supplied from the voltage output terminal 5014 of the voltage / current supply circuit 5011 is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011, and the steady state is obtained. That is, the signal writing And when the body has been completed, it becomes substantially equal to the voltage value. That is, (W23 / L23) = (W115 / L115) × ξ / π may be set. Then, the gate-source voltage of the transistor 5602 and the gate-source voltage of the transistor 3801 are substantially equal, and supplying a signal voltage from the voltage output terminal 5014 is approximately equal to precharging. . Therefore, when a signal current is supplied from the current output terminal 5013 of the voltage / current supply circuit 5011 after precharging, the steady state can be quickly achieved.

  Next, FIGS. 57 and 58 show a configuration in the case where a current is input to the original signal input terminal 5012. 57 corresponds to FIG. 55 with the addition of a transistor 5701 so that current can be input, and FIG. 58 is the same as FIG. 56 with the addition of a transistor 5801 so that current can be input. It corresponds to. In FIG. 57, a terminal 5504 connects transistors 5101, 5701, 5503, and 5509, and a terminal 5507 connects a transistor 5506 and a transistor 5508. In FIG. 58, a terminal 4104 connects transistors 4105, 4103, and 5602, and a terminal 4102 connects transistors 4101, 5801, and 5601.

  As described above, FIGS. 51 to 58 have described the case where the voltage / current supply circuit 5011 is the discharge type. However, when the set circuit 5021 is a suction type as shown in FIGS. 39 and 40, the voltage / current supply circuit 5011 needs to be a suction type. However, when changing from the discharge type configuration to the suction type configuration, it is only necessary to change the polarity of the transistor. For example, FIG. 59 shows a configuration when FIG. 52 is changed to the suction type. In this way, the polarity of each transistor may be reversed and the potential of each wiring may be changed.

  Next, the configuration of the current storage circuit 5031 in FIG. 50 will be described. The current storage circuit 5031 may have any configuration as long as a current is input from the storage current input terminal 5032 and a current is output from the storage current output terminal 5033.

  As an example, the configuration described in FIG. 21 or FIGS. 22 to 35 may be used. That is, the current input terminal 2102 in FIG. 21 corresponds to the storage current input terminal 5032 of the current storage circuit 5031 in FIG. 50, and the current output terminal 2101 in FIG. 21 corresponds to the storage current output terminal 5033 of the current storage circuit 5031 in FIG. It corresponds to.

FIG. 60 shows an example of a current storage circuit 5031 when the configuration of FIG. 22 is used. Similarly, FIG. 61 shows an example of a current storage circuit when the configuration of FIG. 28 is used, and FIG. 62 shows an example of a current storage circuit when the configuration of FIG. 26 is used. The case of FIG. 60 corresponds to the suction type, the case of FIG. 61 corresponds to the discharge type, and the case of FIG. 62 corresponds to the case where the type is reversed between the current input part and the output part. .

  As described above, the current storage circuit 5031 can be configured by appropriately selecting the suction type or the discharge type.

(Embodiment 6)
In FIG. 50 in the fifth embodiment, the case where the current storage circuit 5031 is inserted is described. That is, in FIG. 50, the signal current is supplied from the current output terminal 5013 to the current storage circuit 5031 from the voltage / current supply circuit 5011. However, the present invention is not limited to this, and a signal voltage and a signal current may be input as shown in FIG.

  FIG. 63 shows a case where a signal voltage and a signal current are input to the current storage circuit 5031.

  As shown in FIG. 63, the signal voltage is output from the second voltage output terminal 6343 of the voltage / current supply circuit 5041 to the current storage circuit 5031 via the switch 6303. This corresponds to a precharge operation. Thereafter, a signal current is output from the current output terminal 5043 to the current storage circuit 5031 via the switch 5003, and current setting is performed in the current storage circuit 5031 to store the current value. Then, a signal voltage is output from the voltage output terminal 5044 of the voltage / current supply circuit 5041 to the set circuit 5021 via the switch 5001 and the output terminal 5022. Therefore, precharge is performed in the circuit 5021 to be set. Thereafter, a signal current is output from the current storage circuit 5031 to the set circuit 5021 via the switch 5002 and the output terminal 5022, and the current is set in the set circuit 5021. Note that the magnitude of the current output from the current storage circuit 5031 to the set circuit 5021 is proportional to the magnitude of the current output from the current output terminal 5043 of the voltage / current supply circuit 5041 to the current storage circuit 5031. Alternatively, depending on the configuration of the current storage circuit 5031, the current storage circuits 5031 are approximately equal.

  In FIG. 63, the voltage / current supply circuit 5041 depends on whether the current storage circuit 5031 and the set circuit 5021 are the suction type or the discharge type, and depending on the polarity of the transistors constituting the circuit. The voltage value to be output needs to be adjusted between the voltage output terminal 5044 and the second voltage output terminal 6343.

  That is, the voltage output from the voltage output terminal 5044 of the voltage / current supply circuit 5041 is sized so as to cause a precharge operation for the set circuit 5021 and output from the second voltage output terminal 6313 of the voltage / current supply circuit 5011. The voltage is set such that the precharge operation for the current storage circuit 5031 is performed.

  The magnitude of each voltage is the same as described in the fourth and fifth embodiments, the current value flowing through each transistor, the polarity of the transistor, the size of the transistor, whether it is a suction type or a discharge type, etc. Can be generated by adjusting.

  First, the configuration of the voltage / current supply circuit 5041 when both the voltage / current supply circuit 5041 and the set circuit 5021 are discharge types will be described.

First, it is assumed that the circuit to be set 5021 is a discharge type and has the configuration of FIG. 37 in which a P-channel transistor 3701 is used. The current storage circuit 5031 is a suction type and has the configuration shown in FIG. FIG. 64 shows an example of the configuration of the voltage / current supply circuit 5041 in that case. It can be said that this is a configuration in which transistors 6401 and 6402 are added to the configuration in FIG. 51, or a gate voltage of the transistor 6401 is output in the configuration in FIG. Therefore, an optimal signal voltage (precharge voltage) can be output by adjusting the current value flowing through each transistor and the transistor size.

  Next, FIG. 65 shows a configuration in the case where the original signal input terminal 5042 is connected to the gate terminal of the N-channel transistor. This can be said to be a configuration in which the gate voltage of the transistor 4101 is output with respect to the configuration of FIG. Therefore, an optimal signal voltage (precharge voltage) can be output by adjusting the current value flowing through each transistor and the transistor size.

  Next, a configuration in the case where a current is input to the original signal input terminal 5042 is shown. FIG. 66 shows the case where a current is input to the P-channel transistor 5303. 66 is obtained by adding a P-channel transistor 5303 to the configuration of FIG. That is, in FIG. 64, the gate potential of the transistor 5101 is directly controlled via the original signal input terminal 5012. On the other hand, in FIG. 66, the gate potential of the transistor 5101 is controlled by passing a current through the P-channel transistor 5303. 66 is the same as FIG. 64, and the description thereof is omitted.

Note that the voltage is output to the voltage output terminal 5044 and the second voltage output terminal 6343 via the amplifier circuits 5301a and 5301b. However, the present invention is not limited to this, and may be omitted if it is not necessary to perform impedance conversion. .

  Next, FIG. 67 shows the case where current is input to the N-channel transistor 5401. FIG. 67 is obtained by adding an N-channel transistor 5401 to the structure of FIG. Therefore, detailed description is omitted.

  Next, a voltage / current supply circuit 5041 in the case of the configuration in FIG. 38 in which the circuit to be set 5021 is a discharge type and the transistor 3801 is an N-channel type will be described. Note that for simplicity, terminals 3702 and 3704 are connected in FIG. 38, and the terminal 3705 is connected to an input terminal 5022 of the circuit to be set 5021 (a source terminal of the transistor 3801).

  First, FIG. 68 shows a configuration in the case where a voltage is input to the original signal input terminal 5042 and the original signal input terminal 5042 is connected to the gate terminal of the P-channel transistor 5101. It can be said that this is a configuration in which the gate voltage of the transistor 5506 is output with respect to the configuration of FIG. Therefore, an optimal signal voltage (precharge voltage) can be output by adjusting the current value flowing through each transistor and the transistor size.

Note that the voltage is output to the voltage output terminal 5044 and the second voltage output terminal 6343 via the amplifier circuits 5301a and 5301b. However, the present invention is not limited to this, and may be omitted if it is not necessary to perform impedance conversion. .

  Next, FIG. 69 shows a configuration in which a voltage is input to the original signal input terminal 5042 and the original signal input terminal 5042 is connected to the gate terminal of the N-channel transistor 4101. It can be said that this is a configuration in which the gate voltage of the transistor 4101 is output with respect to the configuration of FIG. Therefore, an optimal signal voltage (precharge voltage) can be output by adjusting the current value flowing through each transistor and the transistor size.

  Next, FIGS. 70 and 71 show a configuration in the case where a current is input to the original signal input terminal 5042. FIG. 70 corresponds to the configuration in which a transistor 5701 is added to FIG. 68 so that a current can be input, and FIG. 71 is a configuration in which a transistor 5801 is added to FIG. 69 so that a current can be input. It corresponds to.

  In FIG. 64, the voltage of the gate terminal is output to the second voltage output terminal 6343, but the present invention is not limited to this. 64, the polarity of the transistor 6402 in FIG. 64 is changed in accordance with the polarity of the transistor in the current storage circuit 5031 to configure the transistor 6202 in FIG. 72, and the source terminal voltage is applied to the second voltage output terminal 6343. You may make it output. The same applies to FIGS.

  As described above, FIGS. 64 to 72 have described the case where the voltage / current supply circuit 5011 and the set circuit 5021 are the discharge type. However, when the set circuit 5021 is a suction type as shown in FIGS. 39 and 40, the voltage / current supply circuit 5011 needs to be a suction type. However, when changing from the discharge type configuration to the suction type configuration, it is only necessary to change the polarity of the transistor. For example, FIG. 73 shows a configuration when FIG. 65 is changed to the suction type. In this way, the polarity of each transistor may be reversed and the potential of each wiring may be changed.

  Thus, various configurations can be achieved by appropriately selecting the suction type or the discharge type.

(Embodiment 7)
In FIG. 50 in the fifth embodiment, the case where the current storage circuit 5031 is inserted between the voltage / current supply circuit 5011 and the set circuit 5021 has been described. As a result, the signal current is temporarily stored and then input to the set circuit 5021. Therefore, similarly, a voltage storage circuit 5051 may be inserted between the voltage / current supply circuit 5011 and the set circuit 5021. FIG. 74 shows a configuration in the case where a voltage storage circuit 5051 is arranged with respect to the configuration in FIG.

  However, the present invention is not limited to this, and the voltage storage circuit 5051 may be arranged in the configuration of FIG. Similarly, in the configuration of FIG. 63, a voltage storage circuit 5051 may be disposed between the voltage / current supply circuit 5041 and the current storage circuit 5031.

  Next, a configuration example of the voltage storage circuit 5051 is shown in FIG. As an element for storing a voltage value, a capacitor element 7501 is provided. An amplifier circuit 7502 is arranged. Note that the amplifier circuit 7502 is a circuit that outputs a potential substantially equal to the input potential, and is preferably a voltage follower circuit or the like. However, the present invention is not limited to this, and a function for converting impedance may be performed. Note that when there is no need to perform impedance conversion, the amplifier circuit 7501 may be omitted.

  Note that as shown in FIG. 76, a plurality of capacitor elements (7501a and 7501b) and amplifier circuits (7502a and 7502b) may be arranged. In that case, as shown in FIG. 77, a voltage having a different magnitude can be output from the storage voltage output terminal 5053 while a voltage is input from the storage voltage input terminal 5052. Thereby, the operation timing can be controlled more flexibly.

  Similarly, as shown in FIG. 78, a plurality of capacitor elements (7501a, 7501b) may be arranged. As a result, the operation timing can be controlled more flexibly.

(Embodiment 8)
In the fourth to seventh embodiments, the circuit for supplying the video signal voltage and the video signal current has been described. In this embodiment, a correspondence relationship in the case where the circuit supplying the video signal voltage and the video signal current described in Embodiments 4 to 7 is applied to the configuration described in Embodiments 1 to 3 will be described.

  First, in the configuration of FIGS. 18, 19, 10, and 20, the video signal voltage and video described in Embodiments 4 to 7 are applied to a portion that supplies a signal to the video current signal line 1801 and the video voltage signal line 101. FIG. 79 shows a configuration in which a circuit for supplying signal current is arranged.

  This corresponds to the case where the configuration of FIG. 50 is applied. That is, the voltage / current supply circuit 5011 in FIG. 50 corresponds to the voltage / current supply circuit 5011 in FIG. 79, and the set circuit 5021 in FIG. 50 corresponds to the pixel in FIGS. The current storage circuit 5031 in FIG. 7 corresponds to the current source circuit 1807a in FIG. With such a configuration, an appropriate signal can be supplied to the pixel and the current source circuit 1807a, and a steady state can be quickly achieved.

  Note that, in the case where voltage storage circuits 1101a to 1101b, 1702aa to 1702bb, and the like are arranged as shown in FIG. 19 and FIG. 17, this corresponds to an application of the configuration of FIG. That is, the voltage storage circuit 5051 in FIG. 74 corresponds to the voltage storage circuits 1101a to 1101b and 1702aa to 1702bb in FIG. 19 and FIG.

In FIG. 79, when the current source 1807a has the configuration shown in FIG. 32, there are a plurality of video current signal lines such as the video current signal line 1801i and the video current signal line 1801j. 88 and 89 show a configuration diagram in that case. A voltage signal is input from the original voltage signal input terminal 8812a, and a voltage signal is input from the original signal input terminal 8812b to supply current. Then, a current is output from the video current signal line 1801i and the video current signal line 1801j. 88 and 89 show the case where there are two video current signal lines, the present invention is not limited to this.

Note that the ratio of the channel width W to the channel length L of the transistors 8901 and 8902 in the voltage / current supply circuit 8811 is obtained by adding the ratio of the channel width W to the channel length L of each transistor. This corresponds to the sum of the current values output from the video current signal line 1801i and the video current signal line 1801j. Therefore, the ratio between the channel width W and the channel length L may be determined on the assumption that the amount of current flowing in the total of the video current signal lines is the largest. As a result, when the magnitude of the current flowing in the total of the video current signal lines is the largest, the magnitude of the voltage signal input from the original voltage signal input terminal 8812a is substantially equal to the voltage signal input from the original signal input terminal 8812b. can do. That is, in the case of FIG. 79 and the like, in the case of FIG. 88 and FIG. 89, the ratio of the channel width W to the channel length L is assumed on the assumption that the current flowing through the total video current signal line is the largest. Can be determined.

Note that as described above, in the transistor 8901 and the transistor 8902, the output current increases in power of two. Therefore, the channel length L may be the same in the transistors 8901, 8902, and the like, and the channel width W may be set to a power of two. Then, the channel width W and the channel length L of the transistors such as the current source circuit 1807a and the pixel may be determined by adding the ratio of the channel width W and the channel length L in each transistor. As a result, when the magnitude of the current flowing through the total video current signal line is the largest, the magnitude of the voltage signal input from the original voltage signal input terminal 8812a is approximately the same as the voltage signal input from the original signal input terminal 8812b. Can be equal.

  Next, FIG. 80 shows a case where the configuration of FIG. 63 is applied. With such a configuration, an appropriate signal can be supplied to the pixel and the current source circuit 1807a, and a steady state can be quickly achieved.

  Next, FIG. 81 shows a case where the configuration of FIG. 36 is applied. With such a configuration, an appropriate signal can be supplied to the current source circuit 1807a and a steady state can be quickly achieved. In FIG. 81, the original signal input terminal 5012 and the video voltage signal line 101 may be connected to apply a signal voltage of the same magnitude.

  As described above, the circuits for supplying the video signal voltage and the video signal current described in the fourth to seventh embodiments can be freely applied to the configurations described in the first to third embodiments.

(Embodiment 9)
In this embodiment mode, a configuration example of a pixel is shown. FIG. 82 shows a configuration example in the case of using a discharge type and a P-channel transistor. First, as shown in FIG. 83, when a signal voltage is input, the switch 1209aa is turned on. However, it may be off. Next, as shown in FIG. 84, a signal current is input.

  After that, current can be supplied to the EL element 8205aa which is a load to emit light. Note that the load is not limited to the EL element 8205aa. An element such as a resistor, a transistor, an EL element, another light emitting element, a current source circuit composed of a transistor, a capacitor, a switch, and the like, a wiring to which an arbitrary circuit is connected, or a signal line, a signal line, It may be a connected pixel. The pixel may include an EL element, an element used in an FED, or an element driven by passing current.

Note that the configuration of the pixel may be any configuration as long as at least a current is input. For example, the configuration shown in FIG. 85 or 86 may be used. Various configurations can be achieved by changing the discharge type or the suction type or changing the polarity of the transistor. Moreover, you may use the structure similar to a current source circuit like FIGS.

  Note that various capacitor elements can be omitted by substituting the gate capacitance of the transistor.

In the various configurations described so far, the switch is arranged in each part, but the arrangement place is not limited to the place already described. A switch can be arranged at an arbitrary place as long as it operates normally.

  The switch may be an electrical switch or a mechanical switch. Any device that can control the flow of current may be used. It may be a transistor, a diode, or a logic circuit combining them. Therefore, when a transistor is used as a switch, the transistor operates as a mere switch, and thus the polarity (conductivity type) of the transistor is not particularly limited. However, when it is desirable that the off-state current is small, it is desirable to use a transistor having a polarity with a small off-state current. As a transistor with low off-state current, there is a transistor provided with an LDD region. In addition, the n-channel type is used when the source terminal potential of a transistor that operates as a switch is close to a low potential side power supply (Vss, Vgnd, 0 V, etc.), while the source terminal potential is a high potential. When operating in a state close to a side power supply (Vdd or the like), it is desirable to use a p-channel type. This is because the absolute value of the voltage between the gate and the source can be increased, so that it can easily operate as a switch. Note that a CMOS switch may be formed using both an n-channel type and a p-channel type.

Note that the transistor in the present invention may be any type of transistor, and may be formed on any substrate. Therefore, glass substrates such as barium borosilicate glass and alumino borosilicate glass, quartz substrates, ceramic substrates, stainless steel substrates, flexible substrates such as plastic and acrylic, single crystal substrates, SOI substrates, and the like are used. Then, all of the circuits as shown in FIG. 1, FIG. 79, FIG. 82, or the like may be formed on these substrates. Alternatively, part of the circuit in FIG. 1, FIG. 79, FIG. 82, or the like may be formed over one substrate, and another part of the circuit in FIG. 1, FIG. 79, or FIG. That is, all of the circuits in FIG. 1, FIG. 79, or FIG. 82 may not be formed over the same substrate. For example, a pixel and a gate line driver circuit are formed using a TFT over a glass substrate, a signal line driver circuit (or part thereof) is formed over a single crystal substrate, and the IC chip is formed by COG (Chip On Glass) may be connected on a glass substrate. Alternatively, the IC chip may be connected to the glass substrate using TAB (Tape Auto Bonding) or a printed board.

(Embodiment 10)
In the first to third embodiments, the case where the signal voltage is input as precharge to the pixel and then the signal current is input is described. However, it is not limited to this.

  For example, it may be operated by inputting only a signal voltage to a pixel or a signal line without inputting a signal current. However, in this case, the luminance of each pixel varies. However, in the case of displaying a moving image or the like, variations in luminance are not noticeable. Therefore, if only the signal voltage is input and the signal current is not input to the pixel or the signal line, the current flowing in each current source portion can be stopped, so that power consumption can be reduced.

  And when displaying a still picture, it becomes easy to recognize the variation in the brightness of each pixel. For this reason, as described in the first to third embodiments, it is desirable to input a signal current after inputting a signal voltage to reduce the influence of luminance variation.

  Thus, the operation when only the signal voltage is input to the pixel or signal line is called the voltage input mode, and the operation when the signal current is input after the signal voltage is input as the precharge is referred to as the current input mode. I will call it.

  In the voltage input mode, it is possible to stop the operation of the current source and the amplifier circuit in each part, so that power consumption can be reduced. However, luminance variation occurs.

  On the other hand, in the current input mode, it is difficult to reduce power consumption, but the influence of luminance variation can be reduced.

  Therefore, the voltage input mode and the current input mode may be switched and operated according to the situation. For example, when a still image is displayed or when a still image is displayed for a predetermined period or longer, it may be operated in the current input mode, and in other cases, it may be operated in the voltage input mode. For example, when a still image is displayed for 1 second or longer, it may be operated as operating in the current input mode.

Alternatively, when an image of a region having a predetermined ratio or more of the display area changes, the image may be operated in the current input mode, and in other cases, the image may be operated in the voltage input mode. For example, when the image changes in an area of more than half of the screen, the operation may be performed in the current input mode.

Alternatively, the two may be combined to operate in the current input mode when the image changes in a predetermined period or in a predetermined region, and may be operated in the voltage input mode otherwise.

(Embodiment 11)
As an electronic device using the present invention, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, a sound reproduction device (car audio, audio component, etc.), a personal computer, a game device, a portable information terminal (mobile) A computer, a mobile phone, a portable game machine, an electronic book, or the like), an image playback device including a recording medium (specifically, a display capable of playing back a recording medium such as a digital versatile disc (DVD) and displaying the image) And the like). Specific examples of these electronic devices are shown in FIGS.

  FIG. 87A illustrates a light-emitting device, which includes a housing 13001, a support base 13002, a display portion 13003, a speaker portion 13004, a video input terminal 13005, and the like. The present invention can be used for an electric circuit included in the display portion 13003. Further, according to the present invention, the light-emitting device shown in FIG. 87A is completed. Since the light-emitting device is a self-luminous type, a backlight is not necessary and a display portion thinner than a liquid crystal display can be obtained. Note that the light emitting device includes all display devices for displaying information such as for personal computers, for receiving TV broadcasts, and for displaying advertisements.

  FIG. 87B shows a digital still camera, which includes a main body 13101, a display portion 13102, an image receiving portion 13103, operation keys 13104, an external connection port 13105, a shutter 13106, and the like. The present invention can be used for an electric circuit included in the display portion 13102. Further, according to the present invention, a digital still camera shown in FIG. 87B is completed.

  FIG. 87C illustrates a personal computer, which includes a main body 13201, a housing 13202, a display portion 13203, a keyboard 13204, an external connection port 13205, a pointing mouse 13206, and the like. The present invention can be used for an electric circuit included in the display portion 13203. Further, according to the present invention, the light-emitting device shown in FIG. 87C is completed.

  FIG. 87D illustrates a mobile computer, which includes a main body 13301, a display portion 13302, a switch 13303, operation keys 13304, an infrared port 13305, and the like. The present invention can be used for an electric circuit included in the display portion 13302. According to the present invention, the mobile computer shown in FIG. 87D is completed.

  FIG. 87E shows a portable image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 13401, a housing 13402, a display portion A13403, a display portion B13404, a recording medium (such as a DVD). A reading unit 13405, operation keys 13406, a speaker unit 13407, and the like are included. Although the display portion A 13403 mainly displays image information and the display portion B 13404 mainly displays character information, the present invention can be used for an electric circuit constituting the display portions A, B 13403, and 13404. Note that an image reproducing device provided with a recording medium includes a home game machine and the like. Further, the present invention completes the DVD playback apparatus shown in FIG.

  FIG. 87F illustrates a goggle type display (head mounted display), which includes a main body 13501, a display portion 13502, and an arm portion 13503. The present invention can be used for an electric circuit included in the display portion 13502. Further, the goggle type display shown in FIG. 87 (F) is completed by the present invention.

  87G illustrates a video camera, which includes a main body 13601, a display portion 13602, a housing 13603, an external connection port 13604, a remote control reception portion 13605, an image receiving portion 13606, a battery 13607, an audio input portion 13608, operation keys 13609, an eyepiece Part 13610 and the like. The present invention can be used for an electric circuit included in the display portion 13602. According to the present invention, the video camera shown in FIG. 87 (G) is completed.

  FIG. 87H shows a cellular phone, which includes a main body 13701, a housing 13702, a display portion 13703, an audio input portion 13704, an audio output portion 13705, operation keys 13706, an external connection port 13707, an antenna 13708, and the like. The present invention can be used for an electric circuit included in the display portion 13703. Note that the display portion 13703 can suppress current consumption of the mobile phone by displaying white characters on a black background. In addition, the mobile phone shown in FIG. 87H is completed by the present invention.

  If the emission luminance of the luminescent material is increased in the future, the light including the output image information can be enlarged and projected by a lens or the like to be used for a front type or rear type projector.

  In addition, the electronic devices often display information distributed through electronic communication lines such as the Internet and CATV (cable television), and in particular, opportunities to display moving image information are increasing. Since the response speed of the light emitting material is very high, the light emitting device is preferable for displaying moving images.

  In addition, since the light emitting device consumes power in the light emitting portion, it is desirable to display information so that the light emitting portion is minimized. Therefore, when a light emitting device is used for a display unit mainly including character information, such as a portable information terminal, particularly a mobile phone or a sound reproduction device, it is driven so that character information is formed by the light emitting part with the non-light emitting part as the background. It is desirable to do.

  As described above, the applicable range of the present invention is so wide that it can be used for electronic devices in various fields. In addition, the electronic device of this embodiment may use the semiconductor device having any structure described in Embodiments 1 to 10.

6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. FIG. 10 illustrates a structure of a conventional pixel. FIG. 10 is a diagram illustrating an operation of a conventional pixel. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 8A and 8B illustrate operation of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate electronic devices to which the present invention is applied. 6A and 6B illustrate a structure of a semiconductor device of the present invention. 6A and 6B illustrate a structure of a semiconductor device of the present invention.

Claims (6)

A video voltage signal line; a plurality of signal lines; a plurality of voltage control switches; a plurality of current source circuits; and a plurality of current control switches;
The signal line is connected to the video voltage signal line via the voltage control switch;
The semiconductor device, wherein the current source circuit is connected to the signal line through the current control switch. In claim 1,
A semiconductor device comprising a video current signal line for supplying a current to the current source circuit. In claim 1 or 2,
A semiconductor device comprising a drive circuit that sequentially selects the voltage control switch. In claim 2 or 3,
2. A semiconductor device, comprising: a drive circuit that sequentially supplies current from the video current signal line to the current source circuit. In any one of Claims 2 thru | or 4,
Supplying a signal current to the video current signal line;
A semiconductor device comprising a voltage / current supply circuit for supplying a signal voltage to the video voltage signal line. In claim 5,
2. The semiconductor device according to claim 1, wherein the signal voltage is a precharge voltage for a pixel connected to the signal line.

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